int dns_packet_append_name(DnsPacket *p, const char *name, bool allow_compression, size_t *start);
int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *key, size_t *start);
int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start);
+int dns_packet_append_opt_rr(DnsPacket *p, uint16_t max_udp_size, bool edns0_do, size_t *start);
+
+void dns_packet_truncate(DnsPacket *p, size_t sz);
int dns_packet_read(DnsPacket *p, size_t sz, const void **ret, size_t *start);
int dns_packet_read_blob(DnsPacket *p, void *d, size_t sz, size_t *start);
int dns_packet_skip_question(DnsPacket *p);
int dns_packet_extract(DnsPacket *p);
+static inline bool DNS_PACKET_SHALL_CACHE(DnsPacket *p) {
+ /* Never cache data originating from localhost, under the
+ * assumption, that it's coming from a locally DNS forwarder
+ * or server, that is caching on its own. */
+
+ return in_addr_is_localhost(p->family, &p->sender) == 0;
+}
+
enum {
DNS_RCODE_SUCCESS = 0,
DNS_RCODE_FORMERR = 1,